Research and Links around Blockchain Technologies


Decentralized Process Modeling and Instance Tracking

This topic concerns the main approach of my ongoing dissertation on the decentralization of information systems development. It is focused on modeling processes among decentralized peers of a network without a central coordinator.

Research paper and talk at the 2018 European Conference on Information Systems
Software prototype on GitHub

Knowledge Blockchain

With this research project concerning Knowledge Management, conceptual models can be tied to a Knowledge Blockchain in order to immutably store, share and manage the knowledge of organizations.

Knowledge Blockchain at HICSS-51
Project Website


Visualization for the analysis and design of blockchain applications and smart contracts.
Härer, Felix, Fill, Hans-Georg (2019): A Comparison of Approaches for Visualizing Blockchains and Smart Contracts. In: Jusletter IT Weblaw, 21 February 2019, ISSN: 1664-848X, DOI: 10.5281/zenodo.2585575. (BibTeX). Presented at the 22nd International Legal Informatics Symposium / 22. Internationales Rechtsinformatik Symposion (IRIS 2019), February 21-23, 2019, Salzburg, Austria.

Paper Presentation

Proof of Existence

Among the most interesting applications for blockchain technologies are existence proofs. The basic idea is to take a hash of any document – e.g. message, photo, certificate – and have it included in a timestamped block of a blockchain. Later on, a Proof of Existence can be conducted by anyone with access to the document and the blockchain, which could be public or private, by re-computing the hash value of the document. If the re-computed hash value matches the one included in the block, the prior existence of the document can be assumed, specifically at the time when the block was mined. If the hash values do not match, nothing can be deduced.

more to come


Resources, Block Explorers, Statistics, Full Node Software, Smart Contract Platforms

Bitcoin Project

Bitcoin Resources

Bitcoin Developer Resources


Block Explorers

  • Blockchair – comprehensive display of block/transaction data with lots of fields, search capabilities, CSV export, API
  • Smartbit – instant search, also searches data (ASCII) included in transactions with OP_RETURN
  • OXT – visualizations of transactions, UTXOs and more
  • Blockstream – for bitcoin, liquid side chains and testnet, with details such as scripts
  • – supports testnet, Litecoin and others, API
  • – supports testnet, fast and clear design, API
  • – popular open source explorer, based on Bitcore
  • Yogh Blockchain Reader – open source explorer, clear listing of blocks and transactions in hexadecimal representation


Full Node

  • Bitcoin Core is the Wallet and Full Node from the core developers
  • Parity-Bitcoin the parity bitcoin client
  • Bitcore-node is a full node based on Bitcore with API and block explorer
  • Bitnodes – data on full nodes with live map, API

Smart Contract Platforms based on Bitcoin

  • Omni Layer – layer on top of the bitcoin network for distributed exchange and smart property
  • Rootstock / RSK – smart contract execution platform backed by the bitcoin blockchain for smart contracts written in Solidity (compatible to Ethereum)


Resources, Block Explorers, Statistics, Clients, APIs

Ethereum Project

Scaling Approaches

  • Sharding – on-chain scaling, partitions data and stores it distributed in shards
  • Plasma – off-chain scaling by locking ether in smart contracts for starting one or more plasma (side) chains
  • Plasma MVP – minimum viable plasma
  • Plasma Cash – reduces per-user data checking, tokens with fixed denominations like cash bills
  • Raiden – off-chain scaling by building a second layer similar to lightning

Ethereum 2.0

Block Explorers

  • Etherscan – transactions, pending transactions, tokens, API
  • Bloxy – blocks and transactions with visual transaction graph, API
  • Etherchain – fast and clear design
  • Ethplorer – explorer and tokens monitor, API



  • Parity – fast, light-weight client
  • Go Ethereum / Geth – original client written in go
  • DAppNode – linux system with preinstalled node software
  • Harmony – ethereum network node with web interface, uses EthereumJ
  • EthereumJ – ethereum implementation purely in java
  • cpp-ethereum – client implementation written in c++
  • pyethapp – client implementation written in python
  • ethereumjs-lib – implementation of core functions in javascript


  • Blockcypher – transactions, contracts, events etc.
  • Etherest – API for ethereum contracts
  • Infura – platform and API
  • MyEtherAPI – network, transaction data, by

Smart Contracts

Autonomous Prediction Markets and other selected Decentralized Apps on Ethereum

  • DappRadar – popular Dapps
  • State of the Dapps – more Dapps
  • Augur – decentralized oracle and prediction market platform
  • Gnosis – another platform for creating Dapps to make predictions
  • Aragon – platform for decentralized autonomous organizations (DAO) using smart contracts
  • OmiseGo – interoperability network on top of ethereum
  • Cryptokitties – the game which introduced the idea of digital collectibles

Interesting projects for building private or consortium blockchains for enterprises

Blockchain as a Service

  • Google – Not running, yet, will provide a platform for Digital Asset, BlockApps, Hyperledger Fabric, Ethereum
  • Amazon – Ethereum as private or consortium blockchain on an AWS ECS cluster
  • IBM Bluemix – blockchain in the IBM bluemix cloud
  • Microsoft Azure Apps – templates for private or consortium blockchains in the azure cloud
  • Microsoft Azure Blockchain Workbench – a development and deployment environment for blockchains
  • Oracle – blockchain “platform as a service”


Hyperledger is a project of the Linux Foundation.

Blockchain Platforms

  • Dragonchain – open source project stemming from the Disney private blockchain platform
  • – platform for private blockchains, asset tracking

Blockchain Services

  • IBM – blockchain-based products, mostly supply chain management
  • Deloitte – Rubix platform by Deloitte
  • Samsung SDS – Nexledger platform